Method and apparatus for feeding a plurality of tread bands in a process for building tyres for vehicle wheels

ABSTRACT

A method and apparatus for feeding a plurality of tread bands in a process for building tyres for vehicle wheels. Each tread band initially includes, on a side thereof, a service fabric. The tread bands are initially arranged at different heights. The method includes positioning a first auxiliary conveyor belt of an auxiliary collection device including a plurality of juxtaposed auxiliary conveyor belts at a first height corresponding to the height of a first tread band, then, proceeding with the removal of the service fabric from the first tread band while the first tread band is transferred onto the first auxiliary conveyor belt. The method also includes positioning at least one second auxiliary conveyor belt of the auxiliary collection device at at least one second height corresponding to that of at least one second tread band.

The present invention relates to a method and an apparatus for feeding aplurality of tread bands in a process for building tyres for vehiclewheels.

The method and apparatus of the invention are preferably used forbuilding tyres for four-wheeled heavy load vehicle wheels (like lorries,trucks, tractors, articulated lorries, buses, trailers, and othervehicles of this type). Such vehicles in particular belong to categoriesM2˜M3, N2˜N3 and O2˜O4 defined in “Consolidate Resolution of theConstruction of Vehicles (R.E.3) (1997)”, Annex 7, pages 52-59,“Classification and definition of power-driven vehicles and trailers”.

Hereafter, the term “elastomeric material” is used to indicate acomposition comprising at least one elastomeric polymer and at least onereinforcing filler. Preferably, such a composition also comprisesadditives like, for example, a cross-linking agent and/or a plasticizer.Thanks to the presence of the cross-linking agent, such a material canbe cross-linked through heating, so as to form the end product.

The terms “radial” and “axial” and the expressions “radiallyinner/outer” and “axially inner/outer” are used with reference to theradial direction and to the axial direction of a forming support used tobuild one or more components of the tyre. The terms “circumferential”and “circumferentially”, on the other hand, are used with reference tothe annular extension of the aforementioned forming support.

By “side” of a tread band it is intended to indicate the surface that islocated in a radially inner position once the tread band itself is woundon a forming drum.

A tyre for vehicle wheels generally comprises a carcass structurecomprising at least one carcass ply formed from reinforcing cordsincorporated in a matrix of elastomeric material. The carcass ply hasend edges respectively engaged with annular anchoring structures. Thelatter are arranged in the areas of the tyre usually identified with thename “beads” and each of them is normally formed by a substantiallycircumferential annular insert on which at least one filling insert isapplied, in a radially outer position thereof. Such annular inserts arecommonly identified as “bead cores” and they have the task of keepingthe tyre firmly fixed to the anchoring seat specifically provided in therim of the wheel, thus preventing, in operation, the radially inner endedge of the tyre from coming out from such a seat.

Specific reinforcing structures having the function of improving thetorque transmission to the tyre can be provided at the beads.

A crown structure is associated in a radially outer position withrespect to the carcass ply, the crown structure comprising a beltstructure and, in a radially outer position with respect to the beltstructure, a tread band.

The belt structure comprises one or more belt layers arranged radiallyone on top of the other and having textile or metallic reinforcing cordswith a crossed orientation and/or an orientation substantially parallelto the direction of circumferential extension of the tyre.

A layer of elastomeric material, called “under-belt”, can be providedbetween the carcass structure and the belt structure, said layer havingthe function of making the radially outer surface of the carcassstructure as uniform as possible for the subsequent application of thebelt structure.

The tread band is made of elastomeric material too.

A so-called “under-layer” made of elastomeric material can be arrangedbetween the tread band and the belt structure, the under-layer havingproperties suitable for ensuring a steady union of the tread band to thebelt structure.

On the side surfaces of the carcass structure, each extending from oneof the side edges of the tread band up to the respective annularanchoring structure to the beads, respective sidewalls of elastomericmaterial are applied.

With particular reference to the tread band, after it has been made, itis generally stored together with a plurality of other tread bands in asuitable storage device, from which it is later picked up to bedeposited on a forming support.

EP 0 448 407 describes a method for producing tyres of different sizes,in which components of the tyre, including tread bands, are arranged onthree distinct collection and feeding devices. A selective mechanismeach time selects one of the aforementioned collection and feedingdevices to allow the respective components to be fed to a building drum.

U.S. Pat. No. 5,725,703 describes a method for depositing apredetermined piece of a tread strip on a belt building drum. Portionsof tread strips are cut from a continuous tread strip and are collectedin a collection device, from which they are sequentially fed to thebuilding drum along a feeding direction jointing the tail portion of onestrip with the head portion of a subsequent strip, thus forming analmost continuous tread band, which is cut to the required length so asto correspond to the circumference of the building drum.

WO 98/31621 describes an apparatus and a method for removing anon-vulcanized tread band from a collection device. The tread band ispicked up through a bar provided with a plurality of suction cups. Eachsuction cup can be fed selectively for the creation of the vacuum as afunction of the length of the tread band. After the suction cups haveengaged the tread band, the band is lifted from the collection device,turned over by 180° and arranged on a roller conveyor.

The Applicant has observed that in order to achieve a stable couplingbetween tread band and belt structure it is necessary to preserve andprotect the adhesiveness of the side of the tread band intended to beassociated with the belt structure. For this purpose, a service fabricis applied by adhesion on the aforementioned side. Such a service fabricmust be removed before proceeding with the depositing of the tread bandon the forming support.

The Applicant has noted that, due to the strong adhesion of the servicefabric to the tread band, the manual removal operations of the servicefabric require a high physical effort for the operator in charge of thistask. Such a operator is also required to make an equally high physicaleffort to pick up the tread band from the storage device and transfer itto the feeding device for feeding it to the forming support. Indeed, itshould be considered that the tread bands for heavy load vehicles canweigh more than 35 kg and be more than 3.5 metres long.

The Applicant has also noted that the physical effort that the operatoris subjected to is further increased by the high speed and frequencywith which he must perform the aforementioned operations of removal ofthe service fabric from the tread band and of transferring the treadband to the aforementioned feeding device. This is due to the constantneed to have cycle times that are as short as possible in order toincrease productivity.

After all, the Applicant has verified that, with cycle times of theorder for example of a few minutes, the aforementioned operations ofremoval of the service fabric from the tread band and of transferringthe tread band to the feeding device, as well as being particularlytiring for the operator, almost totally occupy all the operator's time,thus preventing him from performing other operations, like for examplethe preparation of other materials to make other tread bands or to buildother components of the tyre.

The Applicant has realised that it is possible to substantially reducethe workload of the operator and at the same time maintain extremelyshort cycle times, ensuring that the operations of removal of theservice fabric and transferring of the tread band to the feeding deviceare both carried out almost entirely automatically, i.e. with a minimalintervention, both in terms of physical effort and in terms of time, bythe operator.

The Applicant has also realised that the almost total automation of theaforementioned operations makes it possible to concentrate in a singleproduction step the execution of such operations for a plurality oftread bands, thus leaving the operator a period of “free time” that issufficiently long to allow him to dedicate himself to other operations.

The Applicant has nevertheless observed that the concentration in asingle production step of the operations of removal of the servicefabric and transferring of the tread band to the feeding devicenecessarily requires the provision, downstream of the station in whichthe removal of the service fabric is carried out, of an auxiliarycollection device for collecting all of the tread bands without theservice fabric. Such an auxiliary collection device must be capable ofcollecting all of the tread bands from which the service fabric isremoved to then transfer them individually and in series to the formingsupport.

The Applicant has, however, noted that the provision of theaforementioned auxiliary collection device inevitably involves anincrease in the floor bulk of the building apparatus, with consequentproblems of layout and plant cost.

The Applicant has thus felt the need to reduce to the minimum the floorbulk of the aforementioned auxiliary collection device, whilst stillsafeguarding the accessibility for the operator, without such areduction in bulk involving a corresponding limitation in the number oftread bands that such an auxiliary collection device is capable ofcollecting in the aforementioned single production step.

The Applicant has finally found that it is possible to satisfy theaforementioned requirement of low bulk without any limitation on thenumber of tread bands and in terms of accessibility making an auxiliarycollection device comprising a plurality of juxtaposed auxiliaryconveyor belts movable along the vertical direction. In this way, theprovision of many juxtaposed auxiliary conveyor belts allows, for thesame bulk in plan, to collect multiple tread bands. The verticalmovement of the belts also allows to bring each belt to a height inwhich it is easily accessible by the operator. The use of belts alsoallows to automatically transfer the individual tread bands to theforming support, thus without the need for intervention by the operator.It is thus possible, after all, to reduce the workload of the operatorand allow him to dedicate himself to other operations, respectingextremely short cycle times and without excessive worsening in terms ofbulk and layout.

The present invention therefore relates, in a first aspect thereof, to amethod for feeding a plurality of tread bands in a process for buildingtyres for vehicle wheels.

Preferably, a plurality of tread bands is provided at different heights,each tread band comprising, on a side thereof, a service fabric.

Preferably, a first auxiliary conveyor belt of an auxiliary collectiondevice is positioned at a first height corresponding to that of a firsttread band of said plurality of tread bands.

Preferably, said auxiliary collection device comprises a plurality ofjuxtaposed auxiliary conveyor belts.

Preferably, said service fabric is removed from said first tread bandwhile said first tread band is transferred onto said first auxiliaryconveyor belt.

Preferably, at least one second auxiliary conveyor belt of saidauxiliary collection device is positioned at at least one second heightcorresponding to that of at least one second tread band of saidplurality of tread bands.

Preferably, said service fabric is removed from said at least one secondtread band while said at least one second tread band is transferred ontosaid at least one second auxiliary conveyor belt.

Preferably, said first tread band and said at least one second treadband are moved in sequence from said first auxiliary conveyor belt andfrom said at least one second auxiliary conveyor belt, respectively,towards a forming support.

The Applicant believes that in this way it is possible to remove theservice fabric from a plurality of tread bands and transfer such treadbands towards the forming support in extremely short cycle times andwithout any physical effort from the operator, moreover leaving theoperator “free time” to dedicate to other operations. All of thiswithout excessive worsening in terms of bulk and layout.

In a second aspect thereof, the invention relates to an apparatus forfeeding a plurality of tread bands in a process for building tyres forvehicle wheels.

Preferably, the apparatus comprises a storage device for storing aplurality of tread bands at different heights, each tread bandcomprising, on a side thereof, a service fabric.

Preferably, the apparatus comprises a separation device for separatingsaid service fabric from each of said tread bands.

Preferably, the apparatus comprises an auxiliary collection device forcollecting each of said plurality of tread bands on a respectiveauxiliary conveyor belt.

Preferably, said auxiliary collection device comprises a plurality ofjuxtaposed auxiliary conveyor belts and can be controlled to positioneach of said auxiliary conveyor belts at a respective height dependingon the height of a respective tread band of said plurality of treadbands.

Preferably, the apparatus comprises a feeding device for feeding each ofsaid tread bands to a forming support.

The Applicant considers that such an apparatus makes it possible toachieve the technical effects discussed above.

The present invention, in at least one of the aforementioned aspects,can have at least one of the following preferred characteristics, takenindividually or in combination.

Preferably, positioning said first auxiliary conveyor belt comprises:

-   -   positioning at said first height a work plane of a separation        device for separating said service fabric;    -   positioning said first auxiliary conveyor belt at a height        substantially equal to said first height.

More preferably, removing said service fabric from said first tread bandcomprises:

-   -   detaching said service fabric from a free end portion of a head        portion of said first tread band to form a detached end edge of        said service fabric;    -   transferring said head portion onto said work plane;    -   completing the detachment of said service fabric from said first        tread band while said first tread band is transferred from said        work plane onto said first auxiliary conveyor belt.

The manual intervention of the operator is thus extremely limited,consisting only in the removal of the service fabric from a limited partof the tread band and in transferring a head portion from the tread bandonto the work plane. The operator therefore, in addition to have areduced physical burden, can advantageously dedicate himself to otheroperations.

In preferred embodiments, completing the detachment of said servicefabric from said first tread band comprises:

-   -   transferring said head portion from said work plane onto said        first auxiliary conveyor belt due to the pulling action of said        detached end edge;    -   moving said first auxiliary conveyor belt;    -   detaching said service fabric due to the movement of said first        auxiliary conveyor belt.

Preferably, positioning said at least one second auxiliary conveyor beltcomprises:

-   -   positioning said work plane at said at least one second height;    -   positioning said at least one second auxiliary conveyor belt at        a height substantially equal to said at least one second height.

More preferably, removing said service fabric from said at least onesecond tread band comprises:

-   -   detaching said service fabric from a free end portion of a head        portion of said at least one second tread band to form a        detached end edge of said service fabric;    -   transferring said head portion onto said work plane;    -   completing the detachment of said service fabric from said at        least one second tread band while said at least one second tread        band is transferred from said work plane onto said at least one        second auxiliary conveyor belt.

Advantageously, the operator repeats the few manual operations carriedout on the first tread band on all the other tread bands, then allowingsuch other tread bands to be processed automatically as occurs for thefirst tread band.

In preferred embodiments, completing the detachment of said servicefabric from said at least one second tread band comprises:

-   -   transferring said head portion from said work plane onto said at        least one second auxiliary conveyor belt due to the pulling        action of said detached end edge;    -   moving said at least one second auxiliary conveyor belt;    -   detaching said service fabric due to the movement of said at        least one second auxiliary conveyor belt.

Preferably, transferring said head portion onto said work planecomprises:

-   -   positioning said head portion on said work plane so that said        free end portion projects cantilevered from said work plane;    -   pulling said detached end edge of said service fabric.

Preferably, moving in sequence said first tread band and said at leastone second tread band from said first auxiliary conveyor belt and fromsaid at least one second auxiliary conveyor belt, respectively, towardsthe forming support comprises:

-   -   transferring in sequence said first tread band and said at least        one second tread band on at least one feeding conveyor belt;    -   transferring in sequence said at least one first tread band and        said at least one second tread band from said at least one        feeding conveyor belt on the forming support.

Advantageously, said at least one feeding conveyor belt can act, in aninitial part of the method and in addition to the aforementionedauxiliary conveyor belts, as a further collection member of a respectivetread band, in this way allowing a greater number of tread bands withoutservice fabric to be collected, with obvious advantages in terms ofprocess cost-effectiveness.

More preferably, transferring in sequence said first tread band and saidat least one second tread band on said at least one feeding conveyorbelt comprises:

-   -   transferring in sequence said first tread band on a first        feeding conveyor belt;    -   transferring said first tread band from said first feeding        conveyor belt to at least one second feeding conveyor belt        arranged between said first feeding conveyor belt and the        forming support;    -   transferring said at least one second tread band on said first        feeding conveyor belt.

The Applicant has verified that the provision of two feeding conveyorbelts makes it possible to achieve an optimal compromise between theaforementioned advantages in terms of process cost-effectiveness andbulk in plan of the apparatus.

Preferably, transferring said at least one second tread band onto saidfirst feeding conveyor belt is carried out at least in partsimultaneously with transferring said first tread band from said firstfeeding conveyor belt to said at least one second feeding conveyor belt.

Preferably, transferring said at least one second tread band onto saidat least one second feeding conveyor belt is carried out at least inpart simultaneously with transferring said first tread band from said atleast one second feeding conveyor belt to the forming support.

It is thus possible, if desired, to temporally juxtapose at least partof the aforementioned operations in order to obtain an advantageousreduction of the cycle time.

Preferably, before transferring in sequence said first tread band andsaid at least one second tread band from said at least one feedingconveyor belt onto the Forming support, said first auxiliary conveyorbelt and said at least one second auxiliary conveyor belt arerespectively brought to a predetermined height. Such a height ispreferably predetermined depending on the height at which said at leastone feeding conveyor belt is located.

Preferably, each of said auxiliary conveyor belts is substantiallyparallel to the other auxiliary conveyor belts.

Preferably, each of said auxiliary conveyor belts is movableupwards/downwards, with respect to a recess of a floor, integrally withthe other auxiliary conveyor belts. The upward/downward movement of allof the auxiliary conveyor belts can thus be carried out through a singlemotorisation.

Preferably, each of said auxiliary conveyor belts is movable along alongitudinal direction independently from the other auxiliary conveyorbelts. In this way the greatest flexibility of management of theindividual auxiliary conveyor belts is obtained, which allows anadvantageous optimisation of the time.

In preferred embodiments thereof, said auxiliary collection devicecomprises a plurality of juxtaposed pressing rollers, each pressingroller of said plurality of pressing rollers being operativelyassociated with a respective auxiliary conveyor belt. Such rollers makeit possible to consolidate the tread band on the respective auxiliaryconveyor belt, thus making easier the dragging of the tread band due tothe movement of the auxiliary conveyor belt.

Preferably, said separation device can be controlled to position a workplane thereof at a plurality of different heights depending on theheight of each tread band of said plurality of tread bands.

More preferably, said auxiliary collection device can be controlled toposition each of said auxiliary conveyor belts at a respective heightdepending on the height of said work plane.

The upward/downward movement of the auxiliary conveyor belts is thusautomatic once the operator has positioned the aforementioned work planeat the tread band to be processed.

Preferably, said separation device comprises a pulling device forpulling a detached end edge of said service fabric.

More preferably, said pulling device is fixedly associated with saidwork plane.

Even more preferably, said pulling device comprises:

-   -   a pair of rollers;    -   a member for controlling the rotation of at least one roller of        said pair of rollers;    -   a contrast roller movable on command between an operative        position in which said contrast roller is in a position proximal        to said pair of rollers and cooperates with said pair of rollers        to pull said detached end edge and a rest position in which said        contrast roller is in a position distal from said pair of        rollers.

Preferably, it is foreseen to use a guiding and centring device forguiding and centring said tread bands, wherein said guiding and centringdevice is operatively arranged between said auxiliary collection deviceand said feeding device.

In preferred embodiments, said feeding device comprises a first feedingconveyor belt in a position proximal to said auxiliary collection deviceand at least one second feeding conveyor belt arranged downstream ofsaid first feeding conveyor belt with respect to said auxiliarycollection device.

Preferably, said first feeding conveyor belt and at least one secondfeeding conveyor belt are movable along a longitudinal directionindependently from one another. This contributes to having a greatflexibility of management and an advantageous optimisation of the time.

Further characteristics and advantages of the present invention willbecome clearer from the following detailed description of preferredembodiments thereof, made with reference to the attached drawings. Insuch drawings:

FIG. 1 is a schematic side view of an exemplifying embodiment of anapparatus for feeding a plurality of tread bands in a process forbuilding tyres for vehicle wheels, in accordance with the presentinvention, the apparatus being illustrated in an operative configurationthereof;

FIG. 2 is an schematic enlarged view of a detail of the apparatus ofFIG. 1 in the aforementioned operative configuration;

FIG. 3 is a schematic and enlarged side view of a first portion of theapparatus of FIG. 1 in the aforementioned operative configuration;

FIG. 4 is a schematic and enlarged side view of a second portion of theapparatus of FIG. 1 in a different operative configuration.

In FIG. 1, reference numeral 1 is used to wholly indicate anexemplifying embodiment of an apparatus in accordance with the presentinvention. The apparatus 1 is used to feed a plurality of tread bands,indicated with 100, towards a forming support, indicated with 500, in aprocess for building tyres for vehicle wheels.

Preferably (but not exclusively), the aforementioned tyres are intendedto be mounted on heavy load vehicle wheels, as defined at the beginningof this description.

The feeding direction of the tread bands 100 towards the forming support500 is indicated in FIGS. 1-4 by the arrow A.

For the sake of clarity of illustration, in FIG. 1 reference numeral 100is associated with just some of the illustrated tread bands.

The forming support 500 is preferably a substantially cylindrical drum.As illustrated in detail in FIG. 4, the forming support 500 can bedriven in rotation by a suitable motor group 501 through a suitablemotion transfer member 502. In the specific example herein illustrated,the motion transfer member 502 which is used is a belt.

The tread bands 100 are preferably made through an extrusion process ofa compound made from elastomeric material.

In the specific case in which the tyre is intended to be mounted on aheavy load vehicle wheel, each tread band 100 preferably has thefollowing dimensions:

-   -   length comprised between about 1.5 metres and about 5 metres,        preferably between about 2 metres and about 4 metres, more        preferably between about 2.5 metres and about 3.5 metres;    -   width comprised between about 100 mm and about 500 mm,        preferably between about 130 mm and about 350 mm.

Each tread band 100 also has a weight between about 15 kg and about 40kg, preferably between about 20 kg and about 35 kg.

A service fabric 100 a, illustrated only in FIG. 2 by the thicker line,is attached by adhesivity on the side of each tread band 100(corresponding to the radially inner surface of the tread band 100 whenit is deposited onto the forming support 500). Such a service fabric 100a is preferably made from plastic material, more preferably polythene.It is used to preserve and protect the adhesivity of the aforementionedside, such adhesivity being necessary to then obtain a stable adhesionof the tread band 100 to the belt structure of the tyre being processed.

With reference to FIGS. 1 and 3, the apparatus 1 comprises a storagedevice 10 of the aforementioned tread bands 100, each tread band 100being provided with a respective service fabric 100 a.

The storage device 10 in particular comprises a trolley 11 movable onthe floor S. The trolley 11 is provided with a plurality of shelves 15arranged at different heights with respect to the floor S. Each shelf 15is intended to support a respective tread band 100.

For the sake of clarity of illustration, reference numeral 15 isassociated with just some of the aforementioned shelves. In FIG. 1 eachshelf 15 has a tread band 100 arranged thereon, while in FIG. 3 for thesake of simplicity of illustration a tread band 100 is illustrated justat the highest shelf 15 among those illustrated.

As illustrated in FIG. 1, each shelf 15 is hinged to the trolley 11 at arespective hinge (not illustrated) suitable for allowing the“book-style” opening of the shelf 15.

Each shelf 15 takes up the open position after the tread band 100supported by it has been picked up, in order to then be able to pick upthe tread band 100 supported by the shelf 15 immediately below.

Again with reference to FIGS. 1 and 3, downstream of the storage device10, with reference to the feeding direction A, the apparatus 1 comprisesa separation device 20 for separating the service fabric 100 a from eachtread band 100 picked up from the storage device 10.

The separation device 20 comprises a slide 21, better illustrated inFIG. 2. Such a slide is movable along a vertical direction upon commandof a motor group 22.

The vertical movement of the slide 21 is illustrated in FIGS. 1-3 by thedouble arrow G. FIGS. 1 and 3 also illustrate, with a broken line, theslide 21 in a different operative position thereof.

As illustrated in FIG. 2, a work plane 23 is defined on the uppersurface of the slide 21. The work plane 23 is intended to support eachtread band 100 picked up from the storage device 10 in the removaloperations of the service fabric 100 a.

Due to the command imparted by the motor group 22, the work plane 23 canbe positioned at a plurality of different heights, such heights beingselected depending on the height of the tread band 100 that it is wishedto pick up from the storage device 10.

A pulling device 24 of the service fabric 100 a is mounted on the slide21. The pulling device 24 is thus movable along the vertical directionintegrally with the work plane 23.

In the exemplifying embodiment herein illustrated, the pulling device 24comprises a pair of rollers 25 a, 25 b, both mounted in a fixed positionon the slide 21. At least one of the aforementioned rollers 25 a, 25 bis a motorised roller. The pulling device 24 further comprises an idlecontrast roller 25 c. The contrast roller 25 c is movable between anoperative position in which it is in a position proximal to the rollers25 a, 25 b (such a position is illustrated with a broken line in FIG. 2)and a rest position in which it is in a position distal from the rollers25 a, 25 b (such a position is illustrated with a solid line in FIG. 2).In its operative position, the contrast roller 25 c is at leastpartially arranged between the rollers 25 a and 25 b in the verticaldirection and cooperates with them to pull the service fabric 100 a fromthe lower side of the tread band 100, as will be illustrated hereafter.

The movement of the contrast roller 25 c between the aforementionedoperative position and rest position is obtained upon command of anactuator 26 which, in the exemplifying embodiment illustrated here, isof the pneumatic type. The actuator 26 is pivoted, at one end thereof,to the slide 21 at a hinge 26 a and, at the opposite end thereof, to anend of a lever 27. The other end of the lever 27 is pivoted to the slide21 at a hinge 28. The hinge 28 is also pivoted to an end of anotherlever 29 fixedly connected to the lever 27, whereas the opposite end ofthe lever 29 is coupled with the contrast roller 25 c.

The assembly comprising the actuator 26 and the levers 27 and 29 thusdefines an articulated kinematic mechanism capable of being movedbetween a rest configuration, illustrated with a solid line in FIG. 2and at which the contrast roller 25 c is in the rest position thereof,and an operative configuration, illustrated with a broken line in FIG. 2and at which the contrast roller 25 c is in the operative positionthereof. Starting from the rest configuration, the activation of theactuator 26 causes a rotation of the lever 27 about the hinge 28.Consequently, the lever 29 also rotates about the hinge 28 and moves thecontrast roller 25 c from the rest position to the operative positionthereof. The subsequent deactivation of the actuator 26, on the otherhand, causes an opposite movement of the levers 27 and 29 about thehinge 28 and, consequently, the movement of the contrast roller 25 cfrom the operative position to the rest position thereof.

As illustrated in FIGS. 1 and 3, the apparatus 1 comprises, upstream ofthe separation device 20, a stop element 18 intended to define theposition at which the storage device 10 must be positioned in order tobe able to proceed with the operations of picking up the tread bands 100and removing the service fabric 100 a.

Again with reference to FIGS. 1 and 3, downstream of the separationdevice 20, with reference to the feeding direction A, the apparatus 1comprises an auxiliary collection device 30 for collecting the treadbands 100 picked up from the storage device 10 and from which theservice fabric 100 a has been removed.

The auxiliary device 30 is preferably housed in a recess R of the floorS having a predetermined depth P. Such an auxiliary device 30 comprisesa plurality of juxtaposed auxiliary conveyor belts 31 (four conveyorbelts 31 in the example illustrated here) which are movable integrallywith one another along the vertical direction upon command of a suitablemotor group 32 through a suitable motion transfer device 33 (FIG. 3).

For the sake of clarity of illustration, in FIGS. 1 and 3 referencenumeral 31 is associated with just one of the aforementioned auxiliaryconveyor belts, the one arranged at the top.

The movement of the auxiliary conveyor belts 31 along the verticaldirection is illustrated in FIGS. 1 and 3 by the double arrow B. In suchfigures the auxiliary conveyor belts 31 are also illustrated with abroken line in a different operative position thereof.

Due to the command imparted by the motor group 32, each auxiliaryconveyor belt 31 can be positioned at a plurality of different heightsdepending on the height at which the work plane 23 is positioned and,therefore, on the height of the tread band 100 that it is wished to pickup from the storage device 10.

The auxiliary conveyor belts 31 are substantially parallel to oneanother and are supported by a frame comprising a plurality of uprights34.

Each auxiliary conveyor belt 31 is defined by a respective belt-shapedelement closed in a loop around two opposite support rollers 31 a. Forthe sake of clarity of illustration, in FIG. 3 reference numeral 31 a isassociated with just one pair of support rollers.

The rotation of the aforementioned belt-shaped element around thesupport rollers 31 a causes the movement of the auxiliary conveyor beltsin the longitudinal direction, indicated in FIG. 3 by the arrow E, andthus the movement of the tread bands 100 along the feeding direction A.In order to have each auxiliary conveyor belt 31 moved in thelongitudinal direction independently from the other auxiliary conveyorbelts 31, each auxiliary conveyor belt 31 is associated with arespective motor member 35.

The auxiliary device 30 further comprises, at an end thereof proximal tothe separation device 20, a plurality of juxtaposed pressing rollers 36,each pressing roller 36 being juxtaposed over a respective auxiliaryconveyor belt 31 and being movable between a rest position, illustratedwith a solid line in FIG. 3, in which the pressing roller 36 is in aposition that is distal from the respective auxiliary conveyor belt 31and an operative position, illustrated with a broken line in FIG. 3, inwhich the pressing roller 36 is in a position proximal to the respectiveauxiliary conveyor belt 31. For the sake of clarity of illustration, inFIG. 3 reference numeral 36 is associated with just one of theaforementioned pressing rollers.

In the exemplifying embodiment illustrated here, each pressing roller 36is associated with an end of a respective arm 36 a. All of the arms 36 aare pivoted to an upright 37 which is fixedly associated with theauxiliary conveyor belts 31. The arms 36 a are also associated, at anend opposite to the one in which the pressing rollers 36 are mounted,with a shaft 38 movable along the vertical direction upon the command ofa suitable motor member 39. For the sake of clarity of illustration,reference numeral 36 a is associated just with one of the aforementionedarms.

Due to the movement of the shaft 38 all of the arms 36 a rotate as aunit with each other around the respective pivoting axes to the upright37, thus moving the pressing rollers 36 from their rest position totheir operative position and vice-versa.

As illustrated in FIG. 1, the apparatus 1 comprises, downstream of theauxiliary device 30, a feeding device 40 configured to transfer on theforming support 500 each of the tread bands 100 coming from theauxiliary device 30.

The feeding device 40 comprises a pair of feeding conveyor belts 41 a,41 b that are substantially identical, arranged in series along thefeeding direction A.

The feeding conveyor belt 41 a is arranged in a position proximal to theauxiliary device 30. The feeding conveyor belt 41 b is arrangeddownstream of the feeding conveyor belt 41 a along the feeding directionA; it is thus in a position proximal to the forming support 500.

Each feeding conveyor belt 41 a, 41 b is defined by a respectivebelt-shaped element closed in a loop around two opposite support rollers45 a, 45 b. The rotation of the aforementioned belt-shaped elementaround the respective support rollers 45 a, 45 b causes the movement ofthe respective feeding conveyor belt 41 a, 41 b in the longitudinaldirection, indicated in FIG. 4 by the arrows La and Lb, respectively,and thus the movement of the tread bands 100 along the feeding directionA towards the forming support 500.

The movement of each of the feeding conveyor belts 41 a, 41 b in thelongitudinal direction takes place upon command of a respective motormember 42 a, 42 b. The feeding conveyor belts 41 a, 41 b are thusmovable in the longitudinal direction independently from one another.

The feeding conveyor belts 41 a, 41 b are supported by a frame 43comprising a plurality of uprights 43 a.

A guiding and centring device 50 for guiding and centring the treadbands 100 coming from the auxiliary device 30 is provided between theauxiliary device 30 and the feeding conveyor belt 41 a. Such a guidingand centring device 50 is fixedly associated with the frame 43 andcomprises a plurality of rollers 51 arranged parallel to one anotherwith respective rotation axes perpendicular to the feeding direction A.

Downstream of the feeding conveyor belt 41 b a deposition device 60 fordepositing the tread bands 100 onto the forming support 500 is provided.Such a deposition device 60 is pivoted to an end of the frame 43proximal to the forming support 500 and comprises a plurality of rollers61 arranged parallel to one another with respective rotation axesperpendicular to the feeding direction A.

The deposition device 60 is movable, upon command of a suitable motormember 62, between a rest position (illustrated in FIG. 1 and with abroken line in FIG. 4) in which it is in a position distal from theforming support 500 and an operative position (illustrated with a solidline in FIG. 4) in which it is in a position proximal to the formingsupport 500.

A preferred embodiment of a method for feeding a plurality of treadbands 100 on the forming support 500 in a process for building tyres forvehicle wheels, preferably for heavy load vehicle wheels, in accordancewith the present invention, will be now described. Such a process can becarried out with the apparatus 1 described above.

With reference to FIG. 1, the tread bands 100 are initially stored inthe storage device 10, each tread band 100 with the respective servicefabric 100 a being positioned on a respective shelf 15 of the trolley11.

The tread bands 100 are sequentially picked up from the respectiveshelves 15 and transferred onto respective auxiliary conveyor belts 31of the auxiliary device 30.

Once a tread band 100 has been picked up from a shelf 15 of the storagedevice 10, such a shelf is made to rotate around the respective hingeand brought to an open position so as to allow the operator to pick upthe tread band 100 arranged on the shelf 15 immediately below.

During the movement between storage device 10 and auxiliary device 30each tread band 100 is removed of the respective service fabric at theseparation device 20.

Once the auxiliary device 30 has been filled with a plurality of treadbands 100 deprived of service fabric 100 a, the tread bands 100 aresequentially transferred from the auxiliary device 30 to the formingsupport 500 passing in order through the guiding and centring device 50,the feeding device 40 and the deposition device 60.

With particular reference to FIGS. 1 and 3, the transfer of each treadband 100 from the storage device 10 to the separation device 20initially comprises the positioning of the trolley 11 in the respectiveparking area close to the separation device 20. In particular, theposition of the trolley 11 is determined by the abutment thereof againstthe stop element 18.

The operator then adjusts the height of the work plane 23 so that it isbrought to a height substantially equal to the height of the shelf 15from which it is wished to pick up the tread band 10. Such adjustment iscarried out by commanding a suitable activation software of the motor22, which in turn commands the upward/downward movement of the slide 21.

Once the work plane 23 has been positioned at the desired height, theoperator activates the auxiliary device 30. In particular, once theheight of the work plane 23 has been detected, the automaticupward/downward movement of the auxiliary conveyor belts 31 is commandeduntil an auxiliary conveyor belt 31 is positioned at the same height asthe work plane 23.

With reference to FIGS. 1-3, the operator then takes care of manuallypicking up a head portion 100′ (FIG. 2) of the tread band 100, pullingit towards the separation device 20. Such a head portion 100′ inparticular is laid on the work plane 23, with a free end portion 100″which projects cantilevered from the work plane 23. Before, after orduring the transferring of the head portion 100′ on the work plane 23,the operator manually detaches the service fabric 100 a from the endportion 100″, thus forming a detached end edge 100 a′ of service fabric100 a. Such a detached end edge 100 a′ preferably has a length of 5-10cm.

Such a detached end edge 100 a′ is then brought close to the rollers 25a. By acting on a safety pedal, the operator actuates the actuator 26which in turn commands the movement of the contrast roller 25 c from thework position to the operative position thereon, illustrated in FIG. 2with a broken line. At this point, the detached end edge 100 a′ ofservice fabric 100 a is captured between the rollers 25 a, 25 b and thecontrast roller 25 c. Therefore, once the motorisation of the roller 25a and/or 25 b is activated, the detached end edge 100 a′ is pulled alongthe direction indicated in FIG. 2 with T. Due to this pulling, the treadband is pushed along the feeding direction A and, simultaneously, theservice fabric 100 a is automatically detached from the portion of treadband 100 that each time leaves the work plane 23. This process continuesuntil the end portion 100″ of the tread band 100 reaches the auxiliaryconveyor belt 31. At this point the motor member 35 is activated, theauxiliary conveyor belt 31 is moved along its longitudinal direction andthe tread band 100 is pulled on the auxiliary conveyor belt 31 due tothe friction between auxiliary conveyor belt 31 and tread band 100. Inorder to increase the friction between auxiliary conveyor belt 31 andtread band 100 the pressing rollers 36 a are brought into theiroperative position (illustrated with a broken line in FIG. 3). Thedetachment of the service fabric 100 a from the tread band 100 thenproceeds automatically until the tread band 100 is entirely transferredon the auxiliary conveyor belt 31.

Once the transferring of the tread band 100 on the auxiliary conveyorbelt 31 is completed, the operator goes back towards the trolley 11 toproceed with the transferring operations of a second tread band 100 froma second shelf 15 of the trolley 11 on the work plane 23 of theseparation device 20 and, from here, to a second auxiliary conveyor belt31 of the auxiliary device 30, with simultaneous removal of the servicefabric 100 a from the second tread band. The aforementioned transferringcomprises the positioning of the work plane 23 at a second heightsubstantially equal to that at which the second shelf 15 is located, theautomatic positioning of the second auxiliary conveyor belt 31 at such asecond height and the repetition of the operations described above.

FIGS. 1 and 3 illustrate an operative configuration in which a firsttread band 100 has been entirely transferred onto a first auxiliaryconveyor belt 31 and another tread band 100 is being transferred from ashelf 15 immediately below the one that supported the first tread band100 to an auxiliary conveyor belt 31 immediately above theaforementioned first auxiliary conveyor belt 31.

The operations described above are repeated until respective tread bands100 are loaded on all of the auxiliary conveyor belts 31 of theauxiliary device 30.

Thereafter, the aforementioned first tread band 100 is transferred, dueto the movement of the auxiliary conveyor belt 31, on the feeding device40.

Such transferring comprises the prior positioning of the aforementionedfirst auxiliary conveyor belt 31 at a height corresponding to that ofthe free end of the guiding and centring device 50. The first tread band100 thus passes through the guiding and centring device 50 and istransferred at first above the first feeding conveyor belt 41 a and thenabove the second feeding conveyor belt 41 b. In such an operative stagethe feeding conveyor belts 41 a and 41 b are moved along the respectivelongitudinal directions La and Lb. The tread band 100 is thentransferred on the deposition device 60, which is brought into itsoperative position indicated with a solid line in FIG. 4 and takes careof depositing the tread band 100 on the forming support 500 while thelatter rotates about its rotation axis, thus building a first crownstructure.

During or after the transferring of the tread band 100 on the feedingconveyor belt 41 b, before or during the deposition of theaforementioned tread band 100 on the forming support 500, the processcontinues with the loading on the feeding conveyor belt 41 a of a secondtread band 100 and with the subsequent depositing of the latter on theforming support (after removal of the crown structure which has beenbuilt thereon previously), repeating the operations described above withreference to the first tread band 100.

The aforementioned operations are repeated for all of the tread bandsprovided on the auxiliary device 30.

FIG. 4 shows an operative configuration in which a first tread band isarranged on the feeding conveyor belt 41 b and a second tread band isarranged on the feeding conveyor belt 41 a.

Through the method described above it is possible to reach an operativeconfiguration in which on each feeding conveyor belt 41 a, 41 b and oneach auxiliary conveyor belt 31 a respective tread band 100 is loaded.There is thus the possibility of storing a plurality (six in theexemplifying embodiment described here and illustrated in the drawings)of tread bands 100 deprived of service fabric 100 a before proceedingwith the depositing of each of them on the forming support 500. It isthus possible to have an advantageous concentration of the operations ofpreparing and loading the tread bands 100 on the apparatus 1 in a singleproduction stage, thus leaving the operator a period of “free time” thatis sufficiently long to allow him to dedicate himself to otheroperations.

Of course, a man skilled in the art can bring further modifications andvariants to the invention described above in order to satisfy specificand contingent application requirements, said variants and modificationsin any case being within the scope of protection as defined by thefollowing claims.

1-25. (canceled)
 26. A method for feeding a plurality of tread bands ina process for building tyres for vehicle wheels, comprising: providing aplurality of tread bands at different heights, each tread bandcomprising, on a side thereof, a service fabric; positioning a firstauxiliary conveyor belt of an auxiliary collection device at a firstheight corresponding to a height of a first tread band of said pluralityof tread bands, said auxiliary collection device comprising a pluralityof juxtaposed auxiliary conveyor belts; removing said service fabricfrom said first tread band while said first tread band is transferredonto said first auxiliary conveyor belt; positioning at least one secondauxiliary conveyor belt of said auxiliary collection device at at leastone second height corresponding to a height of at least one second treadband of said plurality of tread bands; removing said service fabric fromsaid at least one second tread band while said at least one second treadband is transferred onto said at least one second auxiliary conveyorbelt; and moving, in sequence, said first tread band and said at leastone second tread band from said first auxiliary conveyor belt and fromsaid at least one second auxiliary conveyor belt, respectively, toward aforming support.
 27. The method according to claim 26, whereinpositioning said fiat auxiliary conveyor belt comprises: positioning atsaid first height a work plane of a separation device for separatingsaid service fabric; and positioning said first auxiliary conveyor beltat a height substantially equal to said first height.
 28. The methodaccording to claim 27, wherein removing said service fabric from saidfirst tread band comprises: detaching said service fabric from a freeend portion of a head portion of said first tread band to form adetached end edge of said service fabric; transferring said head portiononto said work plane; and completing detachment of said service fabricfrom said first tread band while said first tread band is transferredfrom said work plane onto said first auxiliary conveyor belt.
 29. Themethod according to claim 28, wherein completing the detachment of saidservice fabric from said first tread band comprises: transferring saidhead portion from said work plane onto said first auxiliary conveyorbelt due to the pulling action of said detached end edge; moving saidfirst auxiliary conveyor belt; and detaching said service fabric due tothe movement of said first auxiliary conveyor belt.
 30. The methodaccording to claim 27, wherein positioning said at least one secondauxiliary conveyor belt comprises: positioning said work plane at saidat least one second height; and positioning said at least one secondauxiliary conveyor belt at a height substantially equal to said at leastone second height.
 31. The method according to claim 30, whereinremoving said service fabric from said at least one second tread bandcomprises: detaching said service fabric from a free end portion of ahead portion of said at least one second tread band to form a detachedend edge of said service fabric; transferring said head portion ontosaid work plane; and completing the detachment of said service fabricfrom said at least one second tread band while said at least one secondtread band is transferred from said work plane onto said at least onesecond auxiliary conveyor belt.
 32. The method according to claim 31,wherein completing the detachment of said service fabric from said atleast one second tread band comprises: transferring said head portionfrom said work plane onto said at least one second auxiliary conveyorbelt due to the pulling action of said detached end edge; moving said atleast one second auxiliary conveyor belt; and detaching said servicefabric due to movement of said at least one second auxiliary conveyorbelt.
 33. The method according to claim 28, wherein transferring saidhead portion onto said work plane comprises: positioning said headportion on said work plane so that said free end portion projectscantilevered from said work plane; and pulling said detached end edge ofsaid service fabric.
 34. The method according to claim 26; whereinmoving, in sequence, said first tread band and said at least one secondtread band from said first auxiliary conveyor belt and from said atleast one second auxiliary conveyor belt, respectively, toward theforming support comprises: transferring, in sequence, said first treadband and said at least one second tread band on at least one feedingconveyor belt; and transferring, in sequence, said at least one firsttread band and said at least one second tread band from said at leastone feeding conveyor belt on the forming support.
 35. The methodaccording to claim 34, wherein transferring, in sequence, said firsttread band and said at least one second tread band on said at least onefeeding conveyor belt comprises: transferring, in sequence, said firsttread band on a first feeding conveyor belt; transferring said firsttread band from said first feeding conveyor belt to at least one secondfeeding conveyor belt arranged between said first feeding conveyor beltand the forming support; and transferring said at least one second treadband on said first feeding conveyor belt.
 36. The method according toclaim 35, wherein transferring said at least one second tread band ontosaid first feeding conveyor belt is carried out, at least in part,simultaneously with transferring said first tread band from said firstfeeding conveyor belt to said at least one second feeding conveyor belt.37. The method according to claim 35, wherein transferring said at leastone second tread band onto said at least one second feeding conveyorbelt is carried out at least in part simultaneously with transferringsaid first tread band from said at least one second feeding conveyorbelt to the forming support.
 38. The method according to claim 34,comprising, before transferring in sequence said first tread band andsaid at least one second tread band from said at least one feedingconveyor belt onto the forming support, bringing said first auxiliaryconveyor belt and said at least one second auxiliary conveyor belt,respectively, to a predetermined height.
 39. An apparatus for feeding aplurality of tread bands in a process for building tyres for vehiclewheels, comprising: a storage device for storing a plurality of treadbands at different heights, each tread band comprising, on a sidethereof, a service fabric; a separation device for separating saidservice fabric from each of said tread bands; an auxiliary collectiondevice for collecting each of said plurality of tread bands on arespective auxiliary conveyor belt, wherein said auxiliary collectiondevice comprises a plurality of juxtaposed auxiliary conveyor belts andsaid auxiliary collection device can be controlled to position each ofsaid auxiliary conveyor belts at a respective height depending on aheight of a respective tread band of said plurality of tread bands; anda feeding device for feeding each of said tread bands to a formingsupport.
 40. The apparatus according to claim 39, wherein each of saidauxiliary conveyor belts is substantially parallel to other auxiliaryconveyor belts.
 41. The apparatus according to claim 39, wherein each ofsaid auxiliary conveyor belts is movable upward/downward, with respectto a recess of a floor, integrally with the other auxiliary conveyorbelts.
 42. The apparatus according to claim 39, wherein each of saidauxiliary conveyor belts is movable along a longitudinal directionindependently from other auxiliary conveyor belts.
 43. The apparatusaccording to claim 39, wherein said auxiliary collection devicecomprises a plurality of juxtaposed pressing rollers, each pressingroller of said plurality of pressing rollers being operativelyassociated with a respective auxiliary conveyor belt.
 44. The apparatusaccording to claim 39, wherein said separation device can be controlledto position a work plane thereof at a plurality of different heightsdepending on a height of each tread band of said plurality of treadbands, and wherein said auxiliary collection device can be controlled toposition each of said auxiliary conveyor belts at a respective heightdepending on a height of said work plane.
 45. The apparatus according toclaim 39, wherein said separation device comprises a pulling device forpulling a detached end edge of said service fabric.
 46. The apparatusaccording to claim 45, wherein said separation device can be controlledto position a work plane thereof at a plurality of different heightsdepending on a height of each tread band of said plurality of treadbands, and wherein said auxiliary collection device can be controlled toposition each of said auxiliary conveyor belts at a respective heightdepending on the height of said work plane, and wherein said pullingdevice is fixedly associated with said work plane.
 47. The apparatusaccording to claim 45, wherein said puffing device comprises: a pair ofrollers; a member for controlling rotation of at least one roller ofsaid pair of rollers; and a contrast roller movable on command betweenan operative position in which said contrast roller is in a positionproximal to said pair of rollers and cooperates with said pair ofrollers to pull said detached end edge and a rest position in which saidcontrast roller is in a position distal from said pair of rollers. 48.The apparatus according to claim 39, comprising a guiding and centringdevice for guiding and centring said tread bands, wherein said guidingand centring device is operatively arranged between said auxiliarycollection device and said feeding device.
 49. The apparatus accordingto claim 39, wherein said feeding device comprises a first feedingconveyor belt in a position proximal to said auxiliary collection deviceand at least one second feeding conveyor belt arranged downstream ofsaid first feeding conveyor belt with respect to said auxiliarycollection device.
 50. The apparatus according to claim 49, wherein saidfirst feeding conveyor belt and at least one second feeding conveyorbelt are movable along a longitudinal direction independently from oneanother.